Fly ash is one of the surplus products created in the combustion process. In industry, fly ash usually refers to ash produced during combustion of coal and is usually taken from the chimneys of thermal power plants. Currently, in Vietnam burning coal to generate electric energy are necessary. Fly ash discharged occupied huge area and polluting the environment. Thus the study of fly ash recyclin...

A generalized kinetic model for fly ash native carbon oxidation is developed. It is shown that the conversion of fly ash native carbon to CO2 is the result of two simultaneous processes taking place on fly ash surface: the first process (rate constant k2) is the direct oxygen transfer from a metal oxide site to a vacant carbon active site leading to immediate carbon gasification; the second one...

In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase composit...

Leaching of fluoride from fly ash has been studied at different ash/water ratios and temperatures and also over a broad range of pH. The efficiency of leaching was only slightly dependent on the ash/water ratio, thus revealing a solubilitycontrolled mechanism of the process. The efficiency was also independent of the temperature over the range 20 90°C.

The South African mining industry has been the backbone of the country’s economy for much of the past century. Mining has, however, often caused the degradation of productive soils. The amendment of these soils is often very expensive and often not sustainable. The University of Pretoria in cooperation with Eskom TSI, has over the past seven years conducted a series of trials. These trials have...

Unburned carbon (UC) is the major source of organic contaminants in municipal solid waste (MSW) fly ash. So most organic contaminants can be removed by the removal of the UC from the MSW fly ash. In this paper, we first used a technique of column flotation to remove UC from MSW fly ash. The influences of column flotation parameters on the recovery efficiency of UC were systematically studied. I...

Understanding the mechanisms involved in the formation of dioxins in fly ash is necessary in the control of dioxin emission. Dioxins are secondarily formed in a post-combustion zone, which is considered to occur primarily on and in fly ash, as first described by Stiegltiz and Vogg [1]. According to many studies, copper compounds are regarded as influential catalysts that generate large amounts ...

In the present work, fly ash geopolymer based composites including polyester (PES) waste were studied. Specimens of three compositions were prepared: (a) fly ash geopolymer with 5% PES waste; (b) fly ash geopolymer mortar with 5% PES waste; (c) fly ash geopolymer mortar with 6.25% PES waste. Compressive and bending strength measurements, water absorption test and determination of thermal conduc...

Graded fly ash particles have many useful industrial applications due to its fineness and spherical shape. However, grading of fly ash in an industrial scale is a challenging task. The possibility of using hydrocyclones for this purpose has been demonstrated here based on carefully conducted laboratory experiments. The primary objective of this research is to study the effectiveness of a classi...

There is uncertainty as to the rates of coal fly ash needed for optimum physiological processes and growth. In the current study we tested the hypothesis that photosynthetic pigments concentrations and CO(2) assimilation (A) are more sensitive than dry weights in plants grown on media amended with coal fly ash. We applied the Terrestrial Plant Growth Test (Guideline 208) protocols of the Organi...